Stay Well 2025: What is Seasonal Affective Disorder?

As part of Stay Well in 2025, we’re providing resources and advice to help you deal with mental health challenges during the festive season and beyond. One common condition many face, particularly during the winter months, is Seasonal Affective Disorder (SAD). This updated article explores what SAD is, its symptoms, causes, and available treatments—plus how Open Mental Health can support you.

Most of us feel brighter and happier when the sun comes out, so during the winter, we look forward to spring. But for some of us, the dark winter days are more than gloomy—they’re downright depressing. The BBC recently featured an article about winter sadness.

What is Seasonal Affective Disorder (SAD)

According to our partners in the NHS, Seasonal Affective Disorder, sometimes called winter depression, causes a persistent low mood that increases and decreases as the seasons change. For most people, the symptoms are worse during the winter, but some experience SAD symptoms in the summer months and feel better in the colder part of the year.

Symptoms of Seasonal Affective Disorder (SAD)?

People suffering from Seasonal Affective Disorder experience symptoms similar to those of depression but do so repeatedly at certain times of the year—usually autumn or winter. These symptoms might be mild or severe. For some, they significantly impair daily life.

Emotional Symptoms: 

• Persistent low mood
• Anxiety
• Losing pleasure or interest in previously enjoyed activities
• Irritation
• Guilt, despair, or worthlessness
• Reduced self-esteem
• Tearfulness
• Stress
• Reduced libido
• Reluctance to participate in social situations

Physical and Behavioural Indicators: 

• Reduced activity levels
• Lethargy and sleepiness
• Difficulty getting up in the morning
• Problems concentrating
• Increased appetite, cravings for carbohydrate-rich foods, and weight gain

Causes of Seasonal Affective Disorder 

It is theorised that the reduction in sunlight during the autumn and winter months affects our brains—specifically, the hypothalamus. The hypothalamus’s main job is to keep our bodies in a stable state of internal balance. When we receive insufficient sunlight exposure, our hypothalamus may not function correctly, reducing or increasing the melatonin we produce. Melatonin is a hormone associated with sleepiness.

Serotonin, a hormone that impacts mood, sleep, and feelings of hunger, may be affected too. Reduced serotonin is strongly linked to feelings of low mood and depression.

Our circadian rhythm, or body clock, can be thrown off beat by lower light levels—impacting our ability to regulate when we wake up, for example.

However, this would not explain the minority of cases where Seasonal Affective Disorder symptoms are worse in the brighter months. At present, a definitive cause for Seasonal Affective Disorder has yet to be established. Genetics may play a role, as Seasonal Affective Disorder is sometimes found in several members of the same family.

Treatment Options for Seasonal Affective Disorder 

The good news is that seasonal Affective Disorder can be treated, and there are a range of practical ways to address the condition:

Lifestyle Improvements: 
Establishing a healthy exercise routine
Managing stress effectively
Maximising exposure to natural sunlight

Light Therapy: 
Using a light box to replicate sunlight exposure

Talking Therapy: 
Cognitive Behavioural Therapy (CBT) can be effective in dealing with Seasonal Affective Disorder
Antidepressants:
Medications like selective serotonin reuptake inhibitors (SSRIs) can help overcome the symptoms of Seasonal Affective Disorder

How can Open Mental Health help me with SAD?

If you think SAD is affecting your mood, or if you have any other concerns about your mental health or need advice about money matters or housing, you can contact Open Mental Health 24 hours a day, seven days a week via our partners at Mindline Somerset on 0800 138 1692 (calls are free).

We will talk to you about your feelings and help you access a range of free services that might include counselling and support or local exercise, volunteer and peer support groups.  We have a range of experts and interventions that can be tailored to your needs. Please be aware that these services can have waiting lists. However, we always do our utmost to keep these to a minimum.

Alternatively, you can approach your GP and request a referral to Open Mental Health.

In the meantime, we have links to valuable resources on our depression page that can help improve low mood. Take a look and discover useful online utilities, advice and information.